title: Inhibitory effect of silver diamine fluoride on dentine demineralisation and collagen degradation.
abstract: OBJECTIVE
  To investigate the inhibitory effects of 38% silver diamine fluoride (SDF) on demineralised dentine.
  
  
  METHODS
  Human dentine blocks were demineralised and allocated to four groups: SF, F, S and W. The blocks in group SF received a topical application of 38% SDF solution (253,900ppm Ag, 44,800ppm F), group F received a 10% sodium fluoride solution (44,800ppm F), group S received a 42% silver nitrate solution (253,900ppm Ag) and group W received deionised water (control). They were subjected to pH cycling using demineralisation solution (pH 5) and remineralisation solution (pH 7) for 8 days. The surface morphology, crystal characteristics, lesion depth and collagen matrix degradation of the specimens were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-CT testing and spectrophotometry with a hydroxyproline assay.
  
  
  RESULTS
  The surface morphology under SEM showed evident demineralisation with exposed collagen in groups S and W, but not in group SF. Clusters of granular spherical grains were observed in the cross-sections of specimens in groups SF and F. XRD revealed precipitates of silver chloride in groups SF and S. The mean lesion depths (±SD) of groups SF, F, S and W were 182 ± 32μm, 204 ± 26μm, 259 ± 42μm and 265 ± 40μm, respectively (SDF, F<S, W; p<0.01). Groups SF and S had significantly less hydroxyproline liberated from the dentine matrix than groups F and W (p<0.01).
  
  
  CONCLUSIONS
  The use of 38% SDF inhibited demineralisation and preserved collagen from degradation in demineralised dentine.
  
  
  CONCLUSIONS
  SDF application positively influences dentine remineralization.
authors.affiliation: Faculty of Dentistry, The University of Hong Kong, Hong Kong.
authors.forename: May L
authors.initials: ML
authors.lastname: Mei
authors.forename: L
authors.initials: L
authors.lastname: Ito
authors.forename: Y
authors.initials: Y
authors.lastname: Cao
authors.forename: Q L
authors.initials: QL
authors.lastname: Li
authors.forename: Edward C M
authors.initials: EC
authors.lastname: Lo
authors.forename: C H
authors.initials: CH
authors.lastname: Chu
mesh_terms: D000287:Administration, Topical; D002327:Cariostatic Agents / Q000627:therapeutic use*; D011232:Chemical Precipitation; D003094:Collagen / Q000187:drug effects* / Q000648:ultrastructure; D003461:Crystallography; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D017886:Durapatite / Q000032:analysis; D005460:Fluorides, Topical; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006909:Hydroxyproline / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D000644:Quaternary Ammonium Compounds / Q000627:therapeutic use*; D018030:Silver Compounds / Q000032:analysis; D012835:Silver Nitrate / Q000627:therapeutic use; D012969:Sodium Fluoride / Q000627:therapeutic use; D013053:Spectrophotometry; D013997:Time Factors; D017001:Tooth Demineralization / Q000517:prevention & control*; D014089:Tooth Remineralization; D014961:X-Ray Diffraction; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D002327:Cariostatic Agents; D005460:Fluorides, Topical; D000644:Quaternary Ammonium Compounds; D018030:Silver Compounds; D012969:Sodium Fluoride; D003094:Collagen; D017886:Durapatite; D012835:Silver Nitrate; C024633:silver diamine fluoride; C037548:silver chloride; D006909:Hydroxyproline
keywords: Collagen; Demineralisation; Dentine; Hydroxyproline; Remineralisation; Silver diamine fluoride